Endocrine Dysfunction: A clinical perspective Flashcards
what can endocrine disease arise from?
:
hormones can be over/under produced
receptors can malfunction
pathways for hormone removal disrupted
what are the common types of endocrine disease in vet med?
over production due to tumour/hyperplastic tissues
deficiency of hormones due to?
destruction of endocrine tissue
pituitary dependent hyperadrenocorticism?
adenomatous enlargement of pituitary gland - excessive ACTH production
adrenal dependent hyperadrenocorticism?
adrenal adenomas/adenocarcinomas
Iatrogenic hyperadrenocorticism?
excessive exogenous administration of steroid
hyperadrenocorticism?
Cushing disease
middle/older aged dogs - hyperadrenocorticism?
majority are pituitary dependent and the rest are adrenal dependent
who tends to be more affected by hyperadrenocorticism - males/females?
females
clinical signs of hyperadrenocorticism?
PUPD
potbelly/abdominal enlargement
muscle weakness
obesity
panting/increased resp rate
dermatologic manifestation
dermatologic manifestation - examples?
alopecia
thin skin
comedones
cutaneous pigmentation
pyoderma
cortisol has stimulatory effects on?
gluconeogenesis
lipolysis
protein/collagen degradation
sodium/water retention
PTH release
Osteoclast activity
cortisol has inhibitory effects on?
gonadotropin release (FSH and LH)
TSH and GH release
Gonadal steroidogenesis
Vit D and Ca intestinal reabsorption
Immune and inflammatory responses
Hypoadrenocorticism?
Addison’s disease
what is Hypoadrenocorticism a cause for?
cause for primary adrenocortical failure unknown - possibly autoimmune
what dogs can suffer from Hypoadrenocorticism?
young to middle age animals - dogs/horses
standard poodle, WHWT, Great danes
clinical signs of Hypoadrenocorticism? (not very specific)
progressive loss of body condition - weight loss
vomiting
gastroenteritis - recurrent
electrolyte disturbances - aldosterone (mineralocorticoid) - alterations in serum levels of potassium, sodium and chloride - Hyponatreamia
Hyperkalaemia - cause bracycardia weakness
Hypoglyceamic - weakness (impaired gluconeogenesis)
Hyperpigmentation of the skin - no cortisol - so ACTH high - ACTH causes pigmentation
what are parathyroid disorders involved in?
involved in calcium homeostasis
disorders of the parathyroid often related to disorders of calcium and phosphate
PTH controls extracellular calcium concentration
what is hyperparathyroidism due to?
an overactive parathyroid
what are the two types of hyperparathyroidism?
primary and secondary
what is primary hyperparathyroidism?
tumours of the parathyroid leading to over production of PTH
what is secondary hyperparathyroidism?
malnutrition of chronic renal disease - associated with imbalance between calcium and phosphate
clinical signs of hyperparathyroidism?
increased urination
increased thirst
lack of appetite
weakness
calculi - bladder, kidney
coma
bone fractures, soft bones
if hypoparathyroidism occurs, what can it be due to?
due to iatrogenic removal of parathyroid gland during thyroidectomy OR possibly some immune mediated disease can cause it
what happens with lymphocytic parathyroidisits?
chief cells of gland degenerate and are relaced by connective tissues
why can hypoparathyroidism be transient?
due to initial hypercalcaemia that causes atrophy of parathyroid gland
what are the clinical signs generally associated with hypocalcaemia?
muscle tremors
twitches
tetany
restless and nervous
what is panhypopituitarism?
generalised reduction in pituitary hormone
clinical signs associated with lack of secretion of trophic hormones?
weight loss/muscle atrophy
gonadal atrophy
disturbances in water balance - PUPD
sometimes blindness - tumour compressing optic chiasma - blindness of central in origin
bilateral symmetrical alopecia
juvenile onset of disease (dwarfism, retention of puppy coat)
PPID?
pituitary pars intermedia dysfunction - equine cushing’s disease
who does PPID affect?
commonly affects ponies but some large breed horses are affected too
and older horses
what is PPID caused by?
caused by enlargement of pars intermedia (middle portion of the pituitary gland
what does PPID result in?
in increased secretion of hormones but mainly ACTH - thus clinical signs generally associated with excessive cortisol
what are the clinical signs associated w/ excessive cortisol due to PPID?
recurrent laminitis
pot bellied appearance
recurrent skin and resp infection (immunocompromised)
hirsutism - excessive hair growth and retention of coat
lethargy
infertility
